Carburetor



W. A. EDWARDS.

CARBURETOR.

APPLICATION FILEDJULY15.1918.

Patented Apr. 4., E922.

- UNITED sTATEs PATENT oFFlicE.

WILLIAM A. EDWARDS, 0F CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO WEBB JAY, OF CHICAGO, ILLINOIS, AND ONE-HALF T0 STEWART-WARNER SPEEDOM- l,YEITIEJ'RJ CORPORATION, 0F CHICAGO, ILLINOIS, A CORPORATION 0F VIRGINIA..

caminan-moa,

Specification of Letters Patent.

Patented Apr. 4, 1922..

Application filed July 15, 1918. l Serial No. 244,929.

To LZZ whom t may concern.'

Be it known thatl I, WILLIAM A. EDWARDS.,

a subject of the King of Great Britain, residing at Chicago, in the county of Cook and State of Illinois, have invented certainnew and useful Improvements in Carburetors, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

a carburetor which will automatically supply fuel in the proper proportion to the airadmitted, both when the engine is idling with thethrottle closed and when it is running at full speed with the throttle open.

One of the featuresof my invention resides in the fact that the fuel is delivered to the carbureting chamber through an orice of a fixed size and that all needle valves or other adjustable devices for regulating the iow of fuel are eliminated, with the result that a. carburetor constructed in accordance with my invention is extremely simple and cheap to manufacture and since it has'no adjusting devices it is very unlikely to get out of order and cannot be tampered with soas to decrease its efficiency by inexperienced users.

My invention is, furthermore, designed so that the flow of fuel into the carbureting chamberxwill be automatically regulated by the openin and closing movements of the throttle, this regulation being effected -merely bythe changes in the position of the throttle valve disk with respect to the inflowing air and without the employment of valves or other auxiliary devices which are customarily relied upon to control the fuel supply.

In order that m'y invention in one of 4its preferred forms may be readily understood and appreciated by those skilled in the art I have illustrated on the accompanying drawings one practical type of carburetor embodying my invention. Referring to the drawings,

Fig. l 1s a longitudinal sectional view through my carburetor;

Fig. 2 is a transverse sectional view on the line 2-2 of Fig. 1; and

Figs. 3 and l are face views and top plan ielws respectively of my novel throttle valve Figure 5 is an axial section in a plane at right angles to that of Figure 1.

0n the drawings reference character 5 designates generally the carburetor casing which is shaped to provide a Venturi tube 6 and a laterally extending portion 7 forming the top of the float chamber. The tubular portion is provided at one end with a flange 8 by means of which the casing is attached to the manifold of'an engine in the usual way, the opposite end of the casing being open directly to the atmosphere or connected with suitable air heating means if preferred, the air supply being controlled by the usual choker valve 9 adapted to be controlled by the driver through any suitable mechanism.

rIhe Venturi tube 6y is provided in its throat, that is, at or near the apex or point of greatest constriction, with a throttle valve disk 11, which will be later described more in detail'. This disk is rotatably mounted upon the upwardly extending portion 12 of a fuel supply tube 13 which is threaded at 14 into the casing wall and projects at its lower end into the float chamber 15 formed of sheet metal or the like and attached by screws or otherwise to the chamber top 7. Liquid fuel such as gasoline or kerosene is suppliedto the float chamber from a tank float 24 is disposed within the chamber and as the'levelof the liquid in the chamber rises this float will engage the circular portion l@t5-fof the frame and thereby elevate the frame on its pivot so that the valve plug 23 will be forced against its seat to stop the iiow of fuel to the chamber.

The valve disk 11 is provided with a diametral thickened portion 25 whichgis drilled aol chamber 26.

out from the top so as to provide a central lA duct of smaller diameter than the chamber extends downwardly from the center of the disk and the upper end of the tubular member 12 fits into the duct and forms a bearing upon whichthe disk may be rotated. rIhe lupper portion of the chamber 26 is provided with opposed slots or grooves 27 and this upper `.end is closed by a spindle 28 which extends through the top of the casing 5 into the venturi and fits snugly in the chamber of the disk, the spindle being 4provided with ribs 29 which fittingly engage in the slots 27 to insure that the disk will turn with the spindle without lost motion. This spindle is provided at its outer end with an arm 31 which is connected -to a throttle lever of any preferred construction and by means of which the driver may open or close the throttle disk 11 at will. I

It will thus be seen that the center chamber 26 of the disk is in direct communication with the float chamber through the radial duct formed in the disk into which the tube 13 extends. The disk is also provided with another radial duct 32 disposed at right angles to the fuel supply duct and intersecting this duct at the center of the disk so that both ducts are in communication through the chamber 26. That face of the disk which is presented toward the intake end of the venturi when the disk is in closed position is provided with an air inlet opening 33 through which air is admitted to the chamber 26 so that it passes across the top of the fuel supply duct and out the discharge duct 32, thereby drawing a certain quantity of fuel' from the float chamber through the tube 13, which fuel is delivered into the carbureting chamber through the duct 32.

The disk 11 is so shaped that it will substantially close and shut off the Venturi tube when it is swung to closed position with the result that the greater part of` the suction exerted upon the Venturi tube by -the engine cylinders will act to draw air in through the opening 33 across the top of the fuel duct and out through Vthe discharge duct 32. I have found, however, that the direct suction thus exerted is too strong for idling purposes and, consequently, I have reduced the suction and at the Sametime admitted a predetermined quantity of air which mixes with the fuel delivered from the duct 32, by providing the edge of the diskl the venturi by the shape of the venturi Vfered by the valve disk.

causes the fuel to flow from the chamber 15 upwardly through the tube 13 into the chamber 26 of the disk, from which it then flows outwardly into the throat of the venturi through the air opening 33 and the discharge duct 32, which at that position of the disk has its discharge mouth, at the edge of the disk, in the low pressure area of the venturi, which is situated a little inward from the apex of the venturi. Under these conditions a maximum amount of fuel is delivered anda high speed mixture of the proper proportions is produced. AAs the engine is throttled down by turning the disk on its axis through the medium of the arm 31 so as to bring the air opening 33 into opposition to the inrushing air, the flow of fuel out through the opening 33 is gradually decreased by the force cf the air and the supply of fuel to the carbureting chamber is correspondingly diminished proportionately to the obstruction to the inlowing air of- As the disk approaches closed position or, in otherwords, a position across the throat of the venturi, the air is drawn inwardly through the opening 33 into the chamber 26 and out through the discharge duct 32. This rapid flow of air across the top of the fuel supply duct 20 causes a certain amount of fuel to be delivered by an injector action from the float chamber into the carbureting chamber. If the throat of the venturi were entirely closed by the disk the amount of fuel delivered would be too large in proportion to the amount of air drawn through the disk, with the result that too rich a mixture would be produced but the notch 34 in the edge of the disk affords a bleed or relief port through which a predetermined quantlty of air is drawn past the disk directly across the mouth of the duct 32 so that it is thoroughly mixed with the fuel delivered by the duct 32 to produce an explosive mixture of the requisite proportions.

It will be manifest, therefore, that I have provided a carburetor which, without the use of needle valves or other auxiliary devices, automatically regulates the flow of gasoline proportionately to the amount of air passing through the carburetor so that a mixture of the right pro ortions is always delivered to the engine. hen the throttle is closed so that the engine is idling the fuel is delivered to the carbureting chamber by an injector action and sufficient supplemental air is admitted through the bleed notch` 34 to produce the proper mixture. When the throttle is wide open the fuel is delivered both through the air intake opening and through the discharge duct directl into the vacuum produced by the venturl, and the maximum amount of fuel is then delivered to the maximum amount of air owing through the venturi so that the proper proportions of the mixture are still maintained. Between the two extremes the flow of fuel is automatically regulated by the action of the air upon the disk which first diminishes the outiiow of fuel `through the opening 33 and then rushes into the opening carrying the fuel out by an injector action through the duct 32. It is believed that my invention and its mode of operation will be understood from the foregoing without further description and it should be noted that my invention is not limited to the structural details illustrated and described but may be embodied in structures which vary materially from that shown without departing from the scope of the invention as defined in the appended claims.

35 is a Well which protrudes from the Venturi tube, 5, down into the float chamber, and has a restricted fuel inlet, 39, at the lower end for admitting fuel from the float chamber, and an atmosphere inlet, 36, to the top. 38 is a slender duct leading from a restricted aperture, 37, which opens intothe Venturi passage justback of or outward from. the

transverse plane of the valve, 11. This duct,

38, opens at its lower end in the lower part of the Well, 35, for intake of fuel from the well. The purpose of this well and its communications as described, is to provide a source of fuel which will respond quickly to the suction when the valve, 11, is open, to provide the extra rich mixture desirable at starting.

I claim:

1. In a carburetor, the combination of a Venturi air intake tube, a valve ldisk rotatably mounted near the apex of the throat of said tube, said disk being provided with radially disposed intersecting intake and discharge ducts, the discharge duct being transverse to theaxis of rotation of the valve, and an opening through a side wall of the disk at the intersection of said ducts, and means for supplying'fuel to said intake duct. i

2. In a carburetor, the combination of a Venturi air intake tube, a valve disk rotatably mounted near the apex of the throat of said tube and provided with radiallydisposed intake and discharge ducts and a centrally disposed air inlet duct, and means for lsupplying fuel to said intake duct, the disand also being provided with an air bleed notch at the outer end of said discharge duct, the discharge duct being transverse'to the axis of rotation of the valve.

4. A carburetor, comprising a Venturi tube, a fuel chamber, a valve disk disposed -near the apex of the throat of said tube, said disk being provided with a central chamber, radially disposed intake and discharge ducts and a lateral air inlet opening, all communicating with said chamber, the discharge duct being transverse to the axis of rotation of the valve, and also being provided with an air bleed notch atl the outer end of said discharge duct, means for supplying fuel from said fuel chamber to said intake duct, and means for controlling the position of said disk in said tube. i

5. A carburetor comprising la Venturi tube and a valve disk rotatably mounted near the apex of the. throat of said tube, said disk being provided with a radial fuel intake duct, an intersecting radial discharge duct transverse to the axis of rotation of the valve, a lateral air inlet opening communicating with the intersection of said ducts, and a peripheral notch at the outer lend of said discharge duct.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 14th day of June, 1917.

WILLIAM A. EDWARDs. 

